Oxide electrolyte sintered body and method for producing the same

Abstract

An oxide electrolyte sintered body with high lithium ion conductivity and a method for producing the same, which can obtain the oxide electrolyte sintered body with high lithium ion conductivity by sintering at lower temperature than ever before. The method for producing an oxide electrolyte sintered body may comprise the steps of: preparing crystal particles of a garnet-type ion-conducting oxide which comprises Li, H, at least one kind of element L selected from the group consisting of an alkaline-earth metal and a lanthanoid element, and at least one kind of element M selected from the group consisting of a transition element that can be 6-coordinated with oxygen and typical elements belonging to the Groups 12 to 15, and which is represented by a general formula (Li,E,H)LMO(where E is at least one kind of element selected from the group consisting of Al, Ga, Fe and Si, 3≤x−3y−z≤7, 0≤y<0.22, 0<z≤2.8, 2.5≤α≤3.5, 1.5≤β≤2.5, and 11≤γ≤13); preparing a lithium-containing flux; and sintering a mixture of the crystal particles of the garnet-type ion-conducting oxide and the flux by heating at 400° C. or more and 650° C. or less.